SYSTEM AND METHOD FOR DETERMINING THE LEVEL OF A SUBSTANCE IN A CONTAINER BASED ON MEASUREMENT OF RESONANCE FROM AN ACOUSTIC CIRCUIT THAT INCLUDES UNFILLED SPACE WITHIN THE CONTAINER THAT CHANGES SIZE AS SUBSTANCE IS ADDED OR REMOVED FROM THE CONTAINER

摘要

Level of substance in a container can be determined by exciting vapor in unfilled space within the container. Variable frequency oscillator and emitting transducer can provide signals to excite resonance of vapor. Sensors can measure the peak resonant signal of vapor excited in unfilled space within the container as the amount of substance in the container changes. A signal-processing unit coupled to the sensor and variable frequency oscillator can process signals sensed by the sensing transducer and can extract them from background noise affecting the acoustic signal of the system using correlation functions by referencing the signal generated by the variable frequency oscillator. A computer can obtain the sign processed by the signal-processing unit and calculate the unfilled space within the container and derive there from an amount of filled space representing the amount of the substance contained therein. A gauge can indicate the amount of substance in the container.

主权项

1. A system for measuring the level of a substance in a container, comprising:
an emitting transducer providing a signal generated by a variable frequency oscillator to excite acoustic resonance of an acoustic circuit represented by a container having an unfilled space filled with a vapor analogous to a capacitor of an acoustic circuit, and a tube analogous to an inductor of an acoustic circuit, wherein the vapor experiences friction as it moves within the tube, which is analogous to a resistor of an acoustic circuit; a sensing transducer measuring amplitude of the signal as it changes as the circuit achieves resonance and as the container is filled or emptied; a speed of sound transducer configured to emit and detect a signal ping inside said container to determine a speed of sound in said container; and a signal processing unit coupled to the sensing transducer and the variable frequency oscillator driving the emitting transducer, said signal processing unit processing the signal sensed by the sensing transducer to extract it from background noise using correlation functions by referencing the signal generated by the variable frequency oscillator.